This is an application for a Mentored Clinical Scientist Development Award (K08). The Applicant is an accomplished clinician shifting career focus from clinical work and medical education to clinical research. The applicant's primary goal is to pursue a career in clinical research focusing on questions driven by clinical practice. Over the last two years, as a staff member of the newly formed Joint Massachusetts General Hospitals-McLean Hospital Pediatric Psychopharmacology Program, Dr. Joseph Biederman, Director, the applicant has become increasingly involved in clinically-driven, programmatic research focused on Tourette's Disorder. However, the absence of formal research training and time to devote to research activities have been serious impediments for rapid progress toward the goal of becoming an independent investigator. By permitting the full focus of the applicant's time on achieving the necessary tools to become an independent investigator, this Award will allow the applicant to achieve these goals. During the period of the Award the applicant will develop comprehensive skills in clinical research methodology with a special focus on longitudinal pros-pective studies. This will involve training in the following areas: 1) Exposure to Clinical Research (10 percent effort) including pediatric psychopharmacology, genetics, epidemiology, longitudinal follow-up studies on pediatric psychopharmacology protocols and longitudinal studies of ADHD and related disorders. In addition, she will continue her work with Dr.Jenike's group on the comparative phenomenology of Tourette's Disorder and Obsessive-Compulsive Disorder and neuroimaging. 2) Formal Didactic Training (20 percent effort) This part of the training will allow the applicant to pursue further education in research methodology and techniques. This will include course-work (detailed below) and tutorials at the Harvard School of Public Health in biostatistics and epidemiology. (10 percent effort) The applicant will be tutored by Dr. Nan Laird, Chairman of the Department of Biostatistics at the Harvard School of Public Health, on statistical methods of longitudinal designs (10 percent effort). 3) Exposure to an Established National TS Research Program (5 percent effort): The applicant will meet monthly with Drs. James Leckman (Professor of Psychiatry) and David Pauls (Associate Professor of Genetics) at the Yale Child Study Center on methodologic approaches to TS, including developmental psychopathology, clinical assess-ment, and family studies. 4) Exposure to Basic Neuroscience (5 percent effort): The applicant will meet monthly with Anne Young, M.D., Ph.D., Chairman of the Neurology Service at Massachusetts General Hospital, and an internationally known neuroscientist with longstanding interest in movement disorders and Tourette's Disorder, to review basic neuroscience issues related to Tourette's Disorder. 5) The Candidate's Mentored Research Study (40 percent effort) The applicant proposes a study aimed at systematic character-ization and typology of 150 children and adolescents with Tourette's disorder who will then be followed prospectively over four years. A comparison sample of 50 age, gender and SES matched non-tic psychiatric controls will be assessed and systematically followed over the same period. This study will be supervised and mentored by Dr. Biederman.